Now I don't know the integration time of my AP. if you look at the phase noise ratings of crystal oscillators you will see the noise goes up as the frequency decreases. This 1/f effect may very well translate into enough jitter to cause missed bits.

Uh................well................that 1/f stuff does something more subtle. If you are into "imaging" and "three dimensionality", you must have low 1/f jitter.

I alluded to this over at Greaser's Palace: the gang I work with has come to the conclusion that Allan Deviation is the best way to characterize clocks. Since effective phase noise will go up 6 dB, with every doubling of frequency, you can't always say "x dBc @ 1 Hz" is the magic number. But, with Allan Deviation.............it will stay the same, at any frequency. And the magic number occurs at 0.1 sec. At least that is the conclusion of the cabal in Texas.

Now, what that magic number is...................ain't sayin'! Gotta hold something back in case any consulting work comes along. But, so far, it has held up to scrutiny.

Logged

"Major Danby, sir.""Danby. D-A-N-B-Y.""Take him out and shoot him.""Sir?""I said take him out and shoot him. Can't you hear?"

On 125th AES Show (2008) Keith Johnson presented a master class Sonic Methodology and MythologyUnfortunately I couldn't find any recorded information from this master class on the Net. The letter from Keith is cited, where he explained what was presented.I attended this master class. Essentially he constructed low-bandwidth PLL system and analyzed the error signal (listened). Different optical/copper digital cable in the system revealed in different PLL error signal. Different power cords and their placement also gave different signature in PLL error.More about Keith can be found here

Lemme guess................more "anecdotal evidence". I've spent 20 years trying to convince people to listen to the PLL error signal. I didn't need a TDR to know that cables made a difference. (Still more anecdotal evidence.)

Logged

"Major Danby, sir.""Danby. D-A-N-B-Y.""Take him out and shoot him.""Sir?""I said take him out and shoot him. Can't you hear?"

Actually, to be fair................not sure if the fallout is the fact that some guy has also figured out that sub- 1 Hz jitter is important, or that some putz is selling a $15k clock. Or that the clock probably sucks, because it is just another rubidium standard. Or all 3. (Who knows? Probably all 3, with that bunch.)

Logged

"Major Danby, sir.""Danby. D-A-N-B-Y.""Take him out and shoot him.""Sir?""I said take him out and shoot him. Can't you hear?"

Where and how was it determined that DBT and the simple suite of audio tests commonly used are either adequate or entirely accurate for specifying performance of a system used to stimulate a person's senses? Not "accepted" but determined.

Me thinks that reductionism can only be taken so far, especially when all interactive parameters and dependencies aren't well defined, understood, or worse, just plain ignored. I guess systems thinking might upset their dogma...

It might be SAW based. Hard to tell, since he spends too much time talking about some POC Harley discovered.

Ok the ironic part...........SAWs have a lower noise floor, than multiplier-based clocks. But, not so great, when it comes to 1/f.

But, they may have changed, since I looked at them, a while back.

As for those other 2 guys.......................one contradicts himself, although he would argue that we don't understand what he is saying. (Yeah, think so!?) The other one............ok, I prefer A over B, but I can only say I prefer it, and not that B sucks.

So, I can do a DBT, with one amp in clipping, for most of the time, but I can not say it is worse than the one that sounds good. Go figure. (I'm sure the same rebuttal will apply.)

At the end of the day, no one really cares why they like what they like, as long as they are happy with what they like. But, no.............unless you like it for the right reason(s), then...................hey, wait.............that starts to sound like fascism.

Just this very morning on my joyful commute - now 25 miles longer... - I was listening to some PhD types discussing multi-tasking. PhDs know everything, you know. Anyway, they were saying that the latest serious studies show that the human brain does not really multi-task very well. At all. No need for me to go over the rest.

But, I, already multi-tasking myself by driving and listening, had a flash. Or a stroke. Not sure which.

If you are listening and trying at the same time to do whatever else you do for a DBT, subtle things would become ignored in the primary focus. At least according to these guys.